1. Field of the Invention
The present invention relates to a conductive ball mounting apparatus and a mounting method for mounting conductive balls on pads of a circuit pattern of a work.
2. Description of the Prior Art
As a method of manufacturing a bump work such as a flip-chip, there has been known one in which conductive balls are used. In this method, after the conductive balls such as solder balls are mounted on pads of a circuit pattern of a work, the work is sent into a heating furnace where the conductive balls and solder for soldering the conductive balls are heated to melt, and then the work is cooled to solidify the conductive balls and the solder, thereby forming bumps on the pads of the work.
Meanwhile, as a method for mounting conductive balls on pads of a work, there has been known one in which a suction head is used. In this method, conductive balls received in a container or the like are picked up through vacuum-suction by suction holes formed in an underside of the suction head to be mounted on pads of a work. According to this method, it is advantageously possible to mount the conductive balls on a large number of pads of the work at a time.
Conventionally, a plurality of suction holes corresponding to one work are formed in an underside of a suction head, which is adapted to mount the conductive balls on one work at a time. However, a method in which the conductive balls are mounted on one work at a time, does not result in an improvement in work efficiency. It is therefore contemplated that suction holes corresponding to a plurality of works are formed in the underside of the suction head to permit the conductive balls to be mounted on the plurality of works at one time, i.e., in a single series of actions.
On the other hand, a circuit pattern formed on an upper surface of a work may have a defect such as a bridge or a cavity. In the case where the conductive balls are mounted on the plurality of works at one time by means of the suction head as described above, a work having a defective circuit pattern may be included in the plurality of works, which results in manufacturing a defective bump work. Further, the same may be said of the case where defective works are produced in other processes before the conductive balls are mounted.